mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-05-05 09:49:58 -04:00
db17ba719b
Ensure that all offsets in a login response buffer are within the size
of the allocated response buffer. Any offsets or lengths that surpass
the allocation are likely the result of an incomplete response buffer.
In these cases, a full reset is necessary.
When attempting to login, the ibmvnic device will allocate a response
buffer and pass a reference to the VIOS. The VIOS will then send the
ibmvnic device a LOGIN_RSP CRQ to signal that the buffer has been filled
with data. If the ibmvnic device does not get a response in 20 seconds,
the old buffer is freed and a new login request is sent. With 2
outstanding requests, any LOGIN_RSP CRQ's could be for the older
login request. If this is the case then the login response buffer (which
is for the newer login request) could be incomplete and contain invalid
data. Therefore, we must enforce strict sanity checks on the response
buffer values.
Testing has shown that the `off_rxadd_buff_size` value is filled in last
by the VIOS and will be the smoking gun for these circumstances.
Until VIOS can implement a mechanism for tracking outstanding response
buffers and a method for mapping a LOGIN_RSP CRQ to a particular login
response buffer, the best ibmvnic can do in this situation is perform a
full reset.
Fixes: dff515a3e7 ("ibmvnic: Harden device login requests")
Signed-off-by: Nick Child <nnac123@linux.ibm.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20230809221038.51296-1-nnac123@linux.ibm.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.